Our justification rests upon God's mercy alone and Christ's merit

Calvin's Institutes (1559)
Book 3 of 4 - How We Receive the Grace of Christ

Chapter 18 - Works righteousness wrongly inferred from reward

5-10 - Answering objections

5. 2 Tim 4:8 implies a reward for works. God can't reward us without first graciously forgiving us. Our faith brings about work, by love - Gal 5:6 - but imperfect works that must be forgiven, to be approved by God.

6. Our treasure is to be in heaven - Luke 16:9; 1 Tim 6:17-19; Matt 6:21. We are to lend to God by giving to the poor - Prov 19:17. This helps us be more godly in this life, but we don't earn heavenly treasure by it.

7. 2 Thess 1:5-7; Heb 6:10 say He will reward our sufferings, but the cause isn't our merit, but God's will. Heb 6:10; Rom 8:29; Luke 24:26; Acts 14:22; Gal 6:17; 2 Cor 4:10; Phil 3:10-11. The point is to spur us on to works, and to "strengthen our hope." Augustine says God is our debtor in that He has promised us all things, but not in that He accepts anything from us.

8. Objection: Love is greater than faith, so it must justify, more than faith. 1 Cor 13:2, 13; Col 3:14. Answer: love is greater, but because it endures forever. Faith justifies without any love-based works, but by "God's mercy alone and Christ's merit." "It is as if someone argued that a king is more capable of making a shoe than a shoemaker is because he is infinitely more eminent." If they speak of God's love, it moved Him to send Christ on whom we rely; if they speak of our works of love, they are imperfect and cannot justify.

9. Objection: In Matt 19:17 Jesus says to be justified we must keep the commandments." Answer: He said this to one who was looking only to the law for his salvation. If you can keep it, go for it. But elsewhere, Jesus calls all to Himself for rest - Matt 11:28-30.

10. Objection: if our sin is imputed as unrighteousness, our good deeds can be imputed as righteousness. Answer: Unbelief is the "first defection from God," the root of all other sins. But a good work and a bad work aren't equal opposites, that result in "tighteousness" if you have more good than bad. One sin in a life makes the whole life unrighteous - James 2:10-11.